---
layout: docs
page_title: Vault as the Secrets Backend Data Integration Overview
description: >-
  Overview of the data integration aspects to using Vault as the secrets backend for Consul on Kubernetes.
---

# Vault as the Secrets Backend - Data Integration

## Overview

This topic describes an overview of how to configure Vault and Consul in order to share secrets for use within Consul.

### General Integration Steps 

Generally, for each secret you wish to store in Vault, the process to integrate the data between Vault and Consul on Kubernetes is: 

#### One time setup in Vault
  1. Store the secret in Vault.
  1. Create a Vault policy that authorizes the desired level of access to the secret.
  
#### Setup per Consul datacenter
  1. Create Vault Kubernetes auth roles that link the policy to each Consul on Kubernetes service account that requires access.
  1. Update the Consul on Kubernetes helm chart.

## Prerequisites
Prior to setting up the data integration between Vault and Consul on Kubernetes, you will need to have read and completed the steps in the [Systems Integration](/docs/k8s/installation/vault/systems-integration) section of [Vault as a Secrets Backend](/docs/k8s/installation/vault).

### Example - Gossip Encryption Key Integration

Following the general integration steps, a more detailed workflow for integration of the [Gossip encryption key](/docs/k8s/installation/vault/data-integration/gossip) with the Vault Secrets backend would like the following:


#### One time setup in Vault
  1. Store the secret in Vault.
       - Save the gossip encryption key in Vault at the path `secret/consul/gossip`.
  1. Create a Vault policy that authorizes the desired level of access to the secret.
      - Create a Vault policy that you name `gossip-policy` which allows `read` access to the path `secret/consul/gossip`.

#### Setup per Consul datacenter

  1. Create Vault Kubernetes auth roles that link the policy to each Consul on Kubernetes service account that requires access.
      - Both Consul servers and Consul clients need access to the gossip encryption key, so you create two Vault Kubernetes:
        - A role called `consul-server` that maps the Kubernetes namespace and service account name for your consul servers to the `gossip-policy` created in [step 2](#one-time-setup-in-vault) of One time setup in Vault.
        - A role called `consul-client` that maps the Kubernetes namespace and service account name for your consul clients to the `gossip-policy` created in [step 2](#one-time-setup-in-vault) of One time setup in Vault..
  1. Update the Consul on Kubernetes helm chart.
      - Configure the Vault Kubernetes auth roles created for the gossip encryption key:
        - [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole) is set to the `consul-server` Vault Kubernetes auth role created previously.
        - [`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole) is set to the `consul-client` Vault Kubernetes auth role created previously.

## Secrets to Service Account Mapping 

At the most basic level, the goal of this configuration is to authorize a Consul on Kubernetes service account to access a secret in Vault. 
Below is a mapping of Vault secrets and the Consul on Kubernetes service accounts that need to access them. 
(NOTE: `Consul components` refers to all other services and jobs that are not Consul servers or clients. 
It includes things like terminating gateways, ingress gateways, etc.)

### Primary Datacenter
| Secret | Service Account For | Configurable Role in Consul k8s Helm |
| ------ | ------------------- | ------------------------------------ |
|[ACL Bootstrap token](/docs/k8s/installation/vault/data-integration/bootstrap-token) | Consul server-acl-init job | [`global.secretsBackend.vault.manageSystemACLsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-managesystemaclsrole)|
|[ACL Partition token](/docs/k8s/installation/vault/data-integration/partition-token) | Consul server-acl-init job | [`global.secretsBackend.vault.manageSystemACLsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-managesystemaclsrole)|
|[ACL Replication token](/docs/k8s/installation/vault/data-integration/replication-token) | Consul server-acl-init job | [`global.secretsBackend.vault.manageSystemACLsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-managesystemaclsrole)|
|[Enterprise license](/docs/k8s/installation/vault/data-integration/enterprise-license) | Consul servers<br/>Consul clients | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)|
|[Gossip encryption key](/docs/k8s/installation/vault/data-integration/gossip) | Consul servers<br/>Consul clients | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)|
|[Snapshot Agent config](/docs/k8s/installation/vault/data-integration/snapshot-agent-config) | Consul snapshot agent | [`global.secretsBackend.vault.consulSnapshotAgentRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulsnapshotagentrole)|
|[Server TLS credentials](/docs/k8s/installation/vault/data-integration/server-tls) | Consul servers<br/>Consul clients<br/>Consul components | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)<br/>[`global.secretsBackend.vault.consulCARole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulcarole)|
|[Service Mesh and Consul client TLS credentials](/docs/k8s/installation/vault/data-integration/connect-ca) | Consul servers | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)|
|[Webhook TLS certificates for controller and connect inject](/docs/k8s/installation/vault/data-integration/connect-ca) | Consul controllers<br/>Consul connect inject | [`global.secretsBackend.vault.controllerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-controllerrole)<br />[`global.secretsBackend.vault.connectInjectRole`](/docs/k8s/helm#v-global-secretsbackend-vault-controllerrole)|

### Secondary Datacenters
The mapping for secondary data centers is similar with the following differences:
- There is no use of bootstrap token because ACLs would have been bootstrapped in the primary datacenter.
- ACL Partition token is mapped to both the `server-acl-init` job and the `partition-init` job service accounts.
- ACL Replication token is mapped to both the `server-acl-init` job and Consul service accounts.

| Secret | Service Account For | Configurable Role in Consul k8s Helm |
| ------ | ------------------- | ------------------------------------ |
|[ACL Partition token](/docs/k8s/installation/vault/data-integration/partition-token) | Consul server-acl-init job<br/>Consul partition-init job | [`global.secretsBackend.vault.manageSystemACLsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-managesystemaclsrole)<br/>[`global.secretsBackend.vault.adminPartitionsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-adminpartitionsrole)|
|[ACL Replication token](/docs/k8s/installation/vault/data-integration/replication-token) | Consul server-acl-init job<br/>Consul servers | [`global.secretsBackend.vault.manageSystemACLsRole`](/docs/k8s/helm#v-global-secretsbackend-vault-managesystemaclsrole)<br/>[`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)|
|[Enterprise license](/docs/k8s/installation/vault/data-integration/enterprise-license) | Consul servers<br/>Consul clients | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)|
|[Gossip encryption key](/docs/k8s/installation/vault/data-integration/gossip) | Consul servers<br/>Consul clients | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)|
|[Snapshot Agent config](/docs/k8s/installation/vault/data-integration/snapshot-agent-config) | Consul snapshot agent | [`global.secretsBackend.vault.consulSnapshotAgentRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulsnapshotagentrole)|
|[Server TLS credentials](/docs/k8s/installation/vault/data-integration/server-tls) | Consul servers<br/>Consul clients<br/>Consul components | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)<br/>[`global.secretsBackend.vault.consulClientRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulclientrole)<br/>[`global.secretsBackend.vault.consulCARole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulcarole)|
|[Service Mesh and Consul client TLS credentials](/docs/k8s/installation/vault/data-integration/connect-ca) | Consul servers | [`global.secretsBackend.vault.consulServerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-consulserverrole)|
|[Webhook TLS certificates for controller and connect inject](/docs/k8s/installation/vault/data-integration/connect-ca) | Consul controllers<br/>Consul connect inject | [`global.secretsBackend.vault.controllerRole`](/docs/k8s/helm#v-global-secretsbackend-vault-controllerrole)<br />[`global.secretsBackend.vault.connectInjectRole`](/docs/k8s/helm#v-global-secretsbackend-vault-controllerrole)|
### Combining policies within roles
As you can see in the table above, depending upon your needs, a Consul on Kubernetes service account could have the need to request more than one secret.  In these cases, you will want to create one role for the Consul on Kubernetes service account that is mapped to multiple policies, each of which allows it access to a given secret.  

For example, if your Consul on Kubernetes servers need access to [Gossip encryption key](/docs/k8s/installation/vault/data-integration/gossip), [Consul Server TLS credentials](/docs/k8s/installation/vault/data-integration/server-tls), and [Enterprise license](/docs/k8s/installation/vault/data-integration/enterprise-license), assuming you have already saved the secrets in vault, you would:
1. Create a policy for each secret.
    1. Gossip encryption key

      <CodeBlockConfig filename="gossip-policy.hcl">

      ```HCL
      path "secret/data/consul/gossip" {
        capabilities = ["read"]
      }
      ```

      </CodeBlockConfig>

      ```shell-session
      $ vault policy write gossip-policy gossip-policy.hcl
      ```

    1. Consul Server TLS credentials

      <CodeBlockConfig filename="ca-policy.hcl">

      ```HCL
      path "pki/cert/ca" {
        capabilities = ["read"]
      }
      ```

      </CodeBlockConfig>

      ```shell-session
      $ vault policy write ca-policy ca-policy.hcl
      ```

    1. Enterprise License

      <CodeBlockConfig filename="license-policy.hcl">

      ```HCL
      path "secret/data/consul/license" {
        capabilities = ["read"]
      }
      ```

      </CodeBlockConfig>

      ```shell-session
      $ vault policy write license-policy license-policy.hcl
      ```

1. Create one role that maps the Consul on Kubernetes service account to the 3 policies.
    ```shell-session
    $ vault write auth/kubernetes/role/consul-server \
        bound_service_account_names=<Consul server service account> \
        bound_service_account_namespaces=<Consul installation namespace> \
        policies=gossip-policy,ca-policy,license-policy \
        ttl=1h
    ```

## Detailed data integration guides
The following secrets can be stored in Vault KV secrets engine, which is meant to handle arbitrary secrets:
- [ACL Bootstrap token](/docs/k8s/installation/vault/data-integration/bootstrap-token)
- [ACL Partition token](/docs/k8s/installation/vault/data-integration/partition-token)
- [ACL Replication token](/docs/k8s/installation/vault/data-integration/replication-token)
- [Enterprise license](/docs/k8s/installation/vault/data-integration/enterprise-license)
- [Gossip encryption key](/docs/k8s/installation/vault/data-integration/gossip)
- [Snapshot Agent config](/docs/k8s/installation/vault/data-integration/snapshot-agent-config)

The following TLS certificates and keys can generated and managed by Vault the Vault PKI Engine, which is meant to handle things like certificate expiration and rotation:
- [Server TLS credentials](/docs/k8s/installation/vault/data-integration/server-tls)
- [Service Mesh and Consul client TLS credentials](/docs/k8s/installation/vault/data-integration/connect-ca)
- [Vault as the Webhook Certificate Provider for Consul Controller and Connect Inject on Kubernetes](/docs/k8s/installation/vault/data-integration/webhook-certs)

## Secrets to Service Account Mapping
Read through the [detailed data integration guides](#detailed-data-integration-guides) that are pertinent to your environment.
